1. Field of Invention
This invention generally relates to semiconductor manufacturing equipment and, more particularly, to an apparatus and method for rapid thermal processing of a semiconductor wafer.
2. Related Art
New processing and manufacturing techniques are continuously being developed to make further advancements in the development of semiconductor devices, especially semiconductor devices of decreased dimensions. One such processing technique is know as Rapid Thermal Processing (RTP), which reduces the amount of time that a semiconductor device is exposed to high temperatures during processing. The RTP technique, typically includes irradiating the semiconductor device or wafer with sufficient power to quickly raise the temperature of the wafer and hold it at that temperature for a time long enough to successfully perform a fabrication process, but which avoids such problems as unwanted dopant diffusion that would otherwise occur at the high processing temperatures.
In a typical RTP chamber, even after the power is removed from heat source, the chamber must be allowed to cool before a semiconductor device can be removed from the chamber. The semiconductor device can remain exposed to temperatures for a longer period of time then desired for a given process. In addition, since cooling times can be relatively substantial, the process can be slowed to a point where the rate of production of semiconductors becomes uneconomical.
The present invention provides a heating apparatus and method for isothermally distributing a temperature across the surface of a semiconductor device or wafer during processing. The present invention also provides for the cooling of the chamber at a rate, which improves the throughput of the heating apparatus.
In the present invention, a chamber is provided defining a cavity. Included within the cavity is a processing tube, which is configured to receive a single or multiple semiconductor wafers. As described in greater detail below, a plurality of resistive heating elements are provided and advantageously arranged in the cavity proximate to the processing tube. Preferably, the heating elements are disposed across the chamber and are aligned in close proximity to one another so as to provide an even heating temperature distribution. Advantageously, the resistive heating elements may be positioned to substantially surround the processing tube to provide dual-sided heating of the wafer. Beneficially, the chamber including the heating elements is separable from the processing tube. Advantageously, by separating the heating elements from the processing tube, heat dissipation from the processing tube is accelerated.
In one aspect of the invention, a processing system is provided. The processing system includes a chamber defining an interior cavity. Arranged within the interior cavity are a processing tube assembly and a heating assembly. The heating assembly is moveable relative to the processing tube assembly from a first position where the processing tube assembly is disposed within the heating assembly and a second position where the processing tube assembly is exposed to an internal environment within the interior cavity of the chamber.
In another aspect of the present invention, a processing apparatus is provided. The apparatus includes a processing tube and a heating chamber including a plurality of heating elements. The heating chamber defines an internal space for removably receiving the process tube. The apparatus also includes an actuation mechanism to move the process tube into and out from the internal space.
In yet another aspect of the present invention, a method is provided for conducting a process. The method includes providing a processing system having a process tube disposed in an internal space defined by the processing system; and separating the process tube from the internal space.
In yet another embodiment, an apparatus is provided for conducting a process. The apparatus includes a processing module; a transport module including a transport mechanism coupled to the processing module; and a gate assembly including portions of walls of the transport module which can be moved from a closed position where the transport module is isolated from an external environment to an open position where the transport module is exposed to the external environment. The gate assembly when in the open position provides clearance for the transport mechanism to rise in and out from within the transport module.
Advantageously, the inner temperature of the processing tube can be reduced without substantially reducing the inner temperature of the heating chamber. More specifically, the present invention allows the wafer to be cooled without the need to reduce or shut-off power to the heating elements. Beneficially, the present invention reduces the cycle time required for ramping up a process chamber to a process temperature, cooling wafers to an acceptable handling temperature, and re-heating the process chamber to conduct additional processes.
These and other features and advantages of the present invention will be more readily apparent from the detailed description of the preferred embodiments set forth below taken in conjunction with the accompanying drawings.